Acrylonitrile-butadiene-styrene (hereinafter referred to as ABS) resin, which has stiffness and chemical resistance due to inclusion of acrylonitrile and processability and mechanical strength and aesthetically pleasing appearance due to inclusion of butadiene and styrene, is variously used in automotive parts, electrical and electronic products, office equipment, and the like. Surface gloss and definition of such ABS resin are important factors determining the quality of molded articles.
As examples of factors affecting surface gloss and definition of ABS resin, there are gas, which is generated due to a heat stabilizer, an unreactive monomer, and the like during high-temperature extrusion and injection molding processes, as well as particle size and particle distribution. Accordingly, it is required to reduce the amount of a gas generated during processing of ABS resin so as to improve surface gloss and definition of the resin. However, it is difficult to completely eliminate additives used to impart various characteristics to ABS resin and completely remove unreactive monomers during a processing process of the resin. Therefore, there is a need for a technology for particularly investigating ingredients of gas generated during processing of ABS resin, and thus, reducing a gas generation amount.